Abstract
BACKGROUND: Older adults requiring care often have multiple morbidities that lead to polypharmacy, including the use of potentially inappropriate medications (PIMs), leading to increased medical costs and adverse drug effects. We conducted a cross-sectional study to clarify the actual state of drug prescriptions and the background of polypharmacy and PIMs. METHODS: Using long-term care (LTC) and medical insurance claims data in the Ibaraki Prefecture from April 2018 to March 2019, we included individuals aged ≥ 65 who used LTC services. The number of drugs prescribed for ≥ 14 days and the number of PIMs were counted. A generalized linear model was used to analyze the association between the backgrounds of individuals and the number of drugs; logistic regression analysis was used for the presence of PIMs. PIMs were defined by STOPP-J and Beers Criteria. RESULTS: Herein, 67,531 older adults who received LTC services were included. The median number of total prescribed medications and PIMs was 7(IQR 5-9) and 1(IQR 0-1), respectively. The main PIMs were loop diuretics/aldosterone antagonists (STOPP-J), long-term use of proton pump inhibitors (Beers Criteria), benzodiazepines/similar hypnotics (STOPP-J and Beers Criteria), and nonsteroidal anti-inflammatory drugs (STOPP-J and Beers Criteria). Multivariate analysis revealed that the number of medications and presence of PIMs were significantly higher in patients with comorbidities and in those visiting multiple medical institutions. However, patients requiring care level ≥1, nursing home residents, users of short-stay service, and senior daycare were negatively associated with polypharmacy and PIMs. CONCLUSIONS: Polypharmacy and PIMs are frequently observed in older adults who require LTC. This was prominent among individuals with comorbidities and at multiple consulting institutions. Utilization of nursing care facilities may contribute to reducing polypharmacy and PIMs.